Water heater tank with convex heads

Abstract

A tank for a water-heating appliance including a body, a first head, and a second head. The body includes a first end, a second end, and a longitudinal axis. The body extends along the longitudinal axis from the first end to the second end. The first head includes multiple landings. The first head is coupled to the first end so that the first head is convex and extends away from the body. The longitudinally outermost points of the landings define a first plane perpendicular to the longitudinal axis. The second head includes multiple landings. The second head is identical to the first head except for at least one opening through a landing. The second head is coupled to the second end so that the second head is convex and extends away from the body. The longitudinally outermost points of the landings define a second plane perpendicular to the longitudinal axis.

1. A tank for a water-heating appliance comprising:
 a body including a first end, a second end, and a longitudinal axis, the body extending along the longitudinal axis from the first end to the second end; 
 a first head including a first plurality of landings, the first head coupled to the first end so that the first head is convex and extends away from the body, each of the first plurality of landings including a longitudinally outermost point, the longitudinally outermost points defining a first plane perpendicular to the longitudinal axis; and 
 a second head including a second plurality of landings, the second head identical to the first head except for at least one opening through a landing, the second head coupled to the second end so that the second head is convex and extends away from the body, each of the second plurality of landings including a longitudinally outermost point, the longitudinally outermost points defining a second plane perpendicular to the longitudinal axis. 
 
     
     
       2. The tank of  claim 1 , wherein each landing of the first plurality of landings includes a flat surface and the flat surfaces define the first plane; and
 wherein each landing of the second plurality of landings includes a flat surface and the flat surfaces define the second plane. 
 
     
     
       3. The tank of  claim 2 , wherein the opening is formed through the flat surface of the landing. 
     
     
       4. The tank of  claim 3 , wherein the landings of the first plurality of landings are positioned equiangularly around a center point of the first head; and
 wherein the landings of the second plurality of landings are positioned equiangularly around a center point of the second head. 
 
     
     
       5. The tank of  claim 2 , wherein the landings of the first plurality of landings are positioned equiangularly around a center point of the first head; and
 wherein the landings of the second plurality of landings are positioned equiangularly around a center point of the second head. 
 
     
     
       6. The tank of  claim 1 , wherein each landing of the first plurality of landings is curved; and
 wherein each landing of the second plurality of landings is curved. 
 
     
     
       7. The tank of  claim 6 , wherein the landings of the first plurality of landings are positioned equiangularly around a center point of the first head; and
 wherein the landings of the second plurality of landings are positioned equiangularly around a center point of the second head. 
 
     
     
       8. The tank of  claim 1 , wherein the landings of the first plurality of landings are positioned equiangularly around a center point of the first head; and
 wherein the landings of the second plurality of landings are positioned equiangularly around a center point of the second head. 
 
     
     
       9. An electric water heater comprising:
 a tank including a body, a lower head, and an upper head, the body including an upper end, a lower end, and a longitudinal axis, the body extending along the longitudinal axis from the upper end to the lower end, the lower head including a first plurality of landings, the lower head coupled to the lower end so that the lower head is convex and extends away from the body, each of the first plurality of landings including a longitudinally outermost point, the longitudinally outermost points defining a first plane perpendicular to the longitudinal axis, the upper head including a second plurality of landings, the upper head identical to the lower head except for at least one opening through a landing, the upper head coupled to the upper end so that the upper head is convex and extends away from the body, each of the second plurality of landings including a longitudinally outermost point, and the longitudinally outermost points defining a second plane perpendicular to the longitudinal axis; 
 a jacket surrounding the tank; and 
 a heating element extending into the tank. 
 
     
     
       10. The tank of  claim 9 , further comprising a base shaped to receive the lower head, the base coupled to a lower end of the jacket. 
     
     
       11. The tank of  claim 10 , further comprising a cover coupled to an upper end of the jacket. 
     
     
       12. The tank of  claim 11 , further comprising a spud positioned in the opening and coupled to the corresponding landing. 
     
     
       13. The tank of  claim 12 , further comprising insulation positioned between the tank and the jacket. 
     
     
       14. The tank of  claim 13 , wherein each landing of the first plurality of landings includes a flat surface and the flat surfaces define the first plane; and
 wherein each landing of the second plurality of landings includes a flat surface and the flat surfaces define the second plane. 
 
     
     
       15. The tank of  claim 13 , wherein each landing of the first plurality of landings is curved; and
 wherein each landing of the second plurality of landings is curved. 
 
     
     
       16. The tank of  claim 9  wherein each landing of the first plurality of landings includes a flat surface and the flat surfaces define the first plane; and
 wherein each landing of the second plurality of landings includes a flat surface and the flat surfaces define the second plane. 
 
     
     
       17. The tank of  claim 9 , wherein each landing of the first plurality of landings is curved; and
 wherein each landing of the second plurality of landings is curved. 
 
     
     
       18. The tank of  claim 9 , wherein the landings of the first plurality of landings are positioned equiangularly around a center point of the first head; and
 wherein the landings of the second plurality of landings are positioned equiangularly around a center point of the second head. 
 
     
     
       19. A method of manufacturing a tank for a water-heating appliance, the method comprising:
 forming a first head including a first plurality of landings, each of the first plurality of landings including a longitudinally outermost point, the longitudinally outermost points defining a first plane; 
 forming a second head identical to the first head, the second head including a second plurality of landings, each of the second plurality of landings including a longitudinally outermost point, the longitudinally outermost points defining a second plane; 
 thereafter creating at least one opening through a landing of the second head; 
 providing a body including a first end, a second end, and a longitudinal axis, the body extending along the longitudinal axis from the first end to the second end; 
 coupling the first head to the first end so that the first head is convex and extends away from the body and so that the first plane is perpendicular to the longitudinal axis; and 
 coupling the second head to the second end so that the second head is convex and extends away from the body and so that the second plane is perpendicular to the longitudinal axis. 
 
     
     
       20. A method of manufacturing a head for a water-heating appliance that is usable as one of an electric water heater lower head, an electric water heater upper head, and a gas water heater upper head, the method comprising:
 forming a plurality of identical heads, each head including a plurality of landings; 
 using at least one head of the identical heads as an electric water heater lower head; 
 using at least one head of the identical heads as an electric water heater upper head after creating an opening through a landing of the head; and 
 using at least one head of the identical heads as a gas water heater upper head after creating an opening through a landing and creating a central opening through the head.